mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-05 01:54:09 +08:00
9b174527e7
In the media drivers, the v4l2 core knows about all submodules and calls into them from a common function. However this cannot work if the modules that get called are loadable and the core is built-in. In that case we get drivers/built-in.o: In function `set_type': drivers/media/v4l2-core/tuner-core.c:301: undefined reference to `tea5767_attach' drivers/media/v4l2-core/tuner-core.c:307: undefined reference to `tea5761_attach' drivers/media/v4l2-core/tuner-core.c:349: undefined reference to `tda9887_attach' drivers/media/v4l2-core/tuner-core.c:405: undefined reference to `xc4000_attach' This was working previously, until the IS_ENABLED() macro was used to replace the construct like #if defined(CONFIG_DVB_CX24110) || (defined(CONFIG_DVB_CX24110_MODULE) && defined(MODULE)) with the difference that the new code no longer checks whether it is being built as a loadable module itself. To fix this, this new patch adds an 'IS_REACHABLE' macro, which evaluates true in exactly the condition that was used previously. The downside of this is that this trades an obvious link error for a more subtle runtime failure, but it is clear that the change that introduced the link error was unintentional and it seems better to revert it for now. Also, a similar change was originally created by Trent Piepho and then reverted by teh change to the IS_ENABLED macro. Ideally Kconfig would be used to avoid the case of a broken dependency, or the code restructured in a way to turn around the dependency, but either way would require much larger changes here. Fixes:7b34be71db("[media] use IS_ENABLED() macro") See-also:c5dec9fb24("V4L/DVB (4751): Fix DBV_FE_CUSTOMISE for card drivers compiled into kernel") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
38 lines
1.2 KiB
C
38 lines
1.2 KiB
C
/*
|
|
* Driver for Microtune MT2266 "Direct conversion low power broadband tuner"
|
|
*
|
|
* Copyright (c) 2007 Olivier DANET <odanet@caramail.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*/
|
|
|
|
#ifndef MT2266_H
|
|
#define MT2266_H
|
|
|
|
struct dvb_frontend;
|
|
struct i2c_adapter;
|
|
|
|
struct mt2266_config {
|
|
u8 i2c_address;
|
|
};
|
|
|
|
#if IS_REACHABLE(CONFIG_MEDIA_TUNER_MT2266)
|
|
extern struct dvb_frontend * mt2266_attach(struct dvb_frontend *fe, struct i2c_adapter *i2c, struct mt2266_config *cfg);
|
|
#else
|
|
static inline struct dvb_frontend * mt2266_attach(struct dvb_frontend *fe, struct i2c_adapter *i2c, struct mt2266_config *cfg)
|
|
{
|
|
printk(KERN_WARNING "%s: driver disabled by Kconfig\n", __func__);
|
|
return NULL;
|
|
}
|
|
#endif // CONFIG_MEDIA_TUNER_MT2266
|
|
|
|
#endif
|